I have been experiencing a  shortness of breath when walking up hills or even stairs,  followed by a pain in my chest and a pain under my shoulder blade. I have had all the heart tests going, 3 chest xrays and lung function tests, which I passed with flying colours. I have had numerous blood tests, including a full blood count,which have come back clear. My Dr has no idea what is wrong but I am getting increasingly concerned as this has been going on for 8 months with no improvement. I am generally in good health, with walking, cycling and swimming as my hobbies, but I am unable to do these anymore. Walking on the flat is ok, but any slight incline and the pain starts and I become breathless. Any Suggestions?